Safety ski binding

ABSTRACT

A safety ski binding having a hollow boot fastener adapted to be swung upwardly out of a normal boot fastening position about a transverse shaft and laterally about a vertical shaft counter to arresting forces, an arresting surface provided on the inside on said boot fastener, an arresting member cooperable with said arresting surface, spring means biasing said member in the direction of the boot into engagement with said arresting surface, said arresting surface having a plurality of vertical arresting cams which rise to a vertical release point during a vertical movement relative to the arresting member and superimposed also a plurality of lateral arresting cams which rise to lateral release points during a lateral movement relative to the arresting member, the lateral arresting cams having centers of curvature located on the side of the arresting surface towards the boot, and said arresting member having two arresting projections movable into engagement with the arresting surface on both sides of a central longitudinal plane thereof when the boot fastener is in a central position.

[451 Nov. 18, 1975 Sittmann SAFETY SKI BINDING [75] Inventor: Brigitte Sittmann, Stuttgart,

- Germany [73] Assignee: Vereinigte Baubeschlagiabriken Gretsch & C0., GmbH, Leonberg, Germany [22] Filed: July 30, 1974 [21] Appl. No.: 493,086

[30] Foreign Application Priority Data Aug. 9, 1973 Germanym 2340419 [52] US. Cl 280/11.35 T [51] Int. Cl. A63C 9/08 [58] Field of Search 280/11.35 T

[56] References Cited UNITED STATES PATENTS 3,610,650 10/1970 Korger 280/1 1.35 T 3,649,037 3/1972 Vouthier.... 280/1 1.35 T

3,689,095 9/1972 Salomon 280/11.35 T 3,778,073 12/1973 Salomon 280/1 1.35 T

Primary ExaminerRobert R. Song [57] ABSTRACT A safety ski binding having a hollow boot fastener adapted to be swung upwardly out of a normal boot fastening position about a transverse shaft and laterally about a vertical shaft counter to arresting forces, an arresting surface provided on the inside on said boot fastener, an arresting member cooperable with said arresting surface, spring means biasing said memher in the direction of the boot into engagement with said arresting surface, said arresting surface having a plurality of vertical arresting cams which rise to a vertical release point during a vertical movement relative to the arresting member and superimposed also a plurality of lateral arresting cams which rise to lateral release points during a lateral movement relative to the arresting member, the lateral arresting cams having centers of curvature located on-the side of the arresting surface towards the boot, and said arresting member having two arresting projections movable into engagement with the arresting surface on both sides of a central longitudinal plane thereof when the boot fastener is in a central position.

14 Claims, 11 Drawing Figures US. Patent Nov.18, 1975 Sheet 1 Of5 3,920,256

Fig.1

11a 17 25 my 18 2U Mb U.S. Patent Nov. 18,1975 Sheet 2 of5 3,920,256

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23 Mb 11 11a 2 H 22 1L 1 6 15 if j) so e;

US. Patent Nov. 18,1975 Sheet3 of5 3,920,256

U.S. Patent Nov. 18, 1975 Sheet40f5 3,920,256

US. Patent Nov. 18,1975 Sheet 5 of5 3,920,256

SAFETY SKI BINDING The invention relates to a safety ski binding with a boot fastener which can be swung out of the normal boot fastening position about a transverse shaft upwards and about a vertical shaft to both sides counter to arresting forces, wherein an arresting member spring-loaded in the direction of the boot engages on an arresting surface provided on the inside on the boot fastener having side-by-side a plurality of vertical arresting cams which rise to the vertical release point during a vertical movement relative to the arresting member and superimposed also a plurality of lateral arresting cams which rise to the lateral release points during a lateral movement relative to the arresting member.

In a known binding of this type (U.S. Pat. No. 3,689,095) an arresting ball presses into an arresting depression provided on the inner surface of the boot fastener. However, this causes considerable surface pressures on the arresting depression or the arresting ball, as well as powerful lateral forces on the arresting ball which causes increased friction and therefore varying release forces as well as increased wear. In addition, the arresting surface has an extremely complicated shape which due to its smallness requires precision manufacture.

The problem of the invention is therefore to provide a safety ski binding of the type described hereinbefore where, whilst maintaining a compact construction, the surface pressures on the arresting surface are reduced, thereby ensuring a substantial constancy of the release values.

According to the invention, this problem is solved in that the centres of curvature of the lateral arresting cams are located on the side of the arresting surface towards the boot, and the arresting member has two juxtaposed arresting projections which when the boot fastener is in the central position engage with the arresting surface on both sides of its central longitudinal plane. Therefore, the projections provided according to-the invention engage laterally around the arresting surface and can therefore be positioned at a relatively large distance from the pivot so that the lateral forces on the arresting member, and the surface pressures on thearresting surface are reduced. The arresting surface can be kept relatively narrow because in the case of a lateral release in each case the arresting projection which is in contact with the arresting surface moves relatively inwardly. It is therefore sufficient if the arresting surface merely extends between the two arresting projections. Therefore this construction is relatively simple and therefore economic to manufacture.

According to a preferred embodiment, between the two arresting projections the arresting member is curved in the same direction but somewhat more than the lateral arresting cams. This ensures a very level support of the projections on the arresting surface so that a clean sliding process is ensured during the lateral release in both directions.

Preferably the arresting surface width decreases downwardly so that the spacing of the contact surfaces between arresting member and arresting surfaces decreases downwards. Therefore the lateral release force decreases with increasing vertical release, which is advantageous, because during the vertical release (frontal fall) the skiers leg is subject to a particularly high load. However, with the construction according to the inven- 2 tion the lateral release force is continuously reduced so that the danger of the skiers leg being broken is substantially eliminated.

According to a further embodiment of the invention, the boot fastener has a vertical rotating shaft which is fitted to the housing so as to be pivotable about the transverse shaft and supports the front portion of the boot fastener pivotable about the vertical shaft, whereby the vertical shaft of the boot fastener is located between the transverse shaft and the arresting surface. This construction also contributes to reducing the lateral release force with increasing vertical release because it makes it possible for the arresting surface to extend downwardly close to the vertical shaft.

Preferably the curvatures of the lateral arresting cams and the arresting member are circular. Advantageously the arresting surface comprises two surfaces which are substantially homologous towards the central longitudinal plane.

According to a further variant, the curvature of the radial sections of the arresting surface can increase from top to bottom. As a result, as the vertical release progresses the lateral release force is increased which can be advantageous if, due to other effects (the arresting surface coming closer to the vertical shaft or convergence of the contact surfaces of the two projections) too great a decrease in the lateral release force could occur with a vertical release.

If the safety ski binding according to the invention, which is preferably a heel binding cooperates with a front binding with the possibility of a lateral release, a further embodiment of the invention provides for projections on the housing which with the binding closed cooperate with lugs on the boot fastener in such a way that lateral release is prevented within a predetermined upward pivoting range of the boot fastener. Therefore lateral release can only take place after vertical release has advanced by a predetermined amount. This is particularly advantageous if during a frontal fall the skiers leg is also exposed to torsional stress/In this case the pressure on the ball of the foot is so great that the lateral release of the front binding is no longer secured. However, in this case the vertical release on the heel binding has already advanced to such an extent that the projections and lugs of this embodiment become disengaged and permit a relatively easy lateral release of the heel binding. I

The vertical release cams preferably have a first portion along which a substantially constant holding down force is exerted on the boot fastener whereby this portion is followed by a portion with a rising holding down force which is in turn followed by a peak on which the holding down force disappears. After the peak the cam appropriately falls off whereupon a force occurs on the boot fastener in the opening direction.

According to a further advantageous embodiment, by means of a hand lever the arresting member can be moved away from the arresting surface counter to the spring tension and between the housing and the boot fastener acts a spring which is held open under tension.

In order to further reduce the frictional forces between the arresting member and the arresting surface, according to a further embodiment the front edge of the arresting member is formed by the generatrix of a roller fitted to the arresting member and which rotates about a transverse shaft.

Finally, according to a further embodiment the front portion of the boot fastener is divided in the centre of boot.

3 the binding in the longitudinal direction of the ski and in each case only the right-hand portion is swung out-to the right and the left-hand portion to the left. This embodiment further facilitates the lateral release of the Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, byway of illustration, show preferred embodiments of the present invention and the principles thereof, and what are now considered to be the best modes contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the scope of the appended claims.

FIG. 1 shows a vertical longitudinal section of a safety ski binding according to the invention for a heel in the closed condition;

. FIG. 2, a horizontal sectionof the binding shown in FIG. 1;

FIG. 3 shows a section analogous to FIG. 1 of the same binding opened in the vertical direction;

FIG. 4 shows a horizontal section identical to FIG. 2 of the binding in the lateral released condition;

FIGS. 5a 52 show radial sections along the lines AtoO-EinFIGl;

FIGS. 6 and 7 show horizontal sections of a further embodiment.

According to FIGS. 1 to 4, a housing 12 is fitted in longitudinally displaceable manner to a base plate 28 fixed to a ski. One or more juxtaposed spiral springs 29 on the boot place the housing 12 under a pretension. The displacement of housing 12 brought about by springs 29 is limited by a stop member 40.

According to FIGS. 1 4, to the housing 12 in the upper area is articulated a vertical rotating shaft 11a which in cross-section has the shape of a rectangular frame of the boot fastener 11 which fastens from behind above and the sides of the ski boot. Between the portion of the boot fastener 11 facing the boot and the vertical rotating shaft 11a is provided an articulated connection with a vertical shaft 17. As can be gathered from FIGS. 1 and 3, the joints defining the vertical shaft 17 are arranged at the top and bottom.

As can be seen from the drawing, boot fastener 11 is hollow and has on the inside an arresting surface 13 which cooperates with an arresting member 14 which is pretensioned in the direction of the arresting surface by a spiral spring 26 supported on housing 12. An adjusting screw 30 permits the adjustment of the spring pretension and therefore the release forces.

As can be seen particularly clearly from FIGS. 2, 4 and 5, the radial sections along 0 A to 0 E of arresting surface 13 are segments ofa circle with centres directed towards the boot. The front edge 16 of arresting member 14 is also a segment of a circle but has a smaller radius ,of curvature than the radial sections of arresting surface 13. Thus, with a non-laterally deflected boot fastener 11 according to FIGS. 2 and two contact surfaces 15 are formed between arresting member 14 and arresting surface 13.

In the plan view of FIG. 2 arresting member I4 has two lateral projections 14a, 14b formed by the circular edge 16 terminating outside the contact surfaces 15.

In FIGS. 1 and 3 lugs 20 and 20' fixed to the boot fastener are shown which cooperate with projections 19 In the lower area of boot fastener 11' which is in this 7 case constructed as a heel binding a pedal is provided which is pivotable. about a transverse shaft 33. Accord-' ing to FIG. 3 the downward movement of-pedal 22 is limited in such a way that it can still be engaged by the lowered heel in order to start the closing movement of the binding' According to FIG S. .2 .and 4 inside boot fastener 11 f lateral receiving spaces 23 are provided whichthe arresting member 14 can enter during a lateral release of the boot fastener 11 according to FIG. 4. v

According to FIGS. 1 and 2, between housing 12 and vertical rotating shaft 11a, a spiral or leg spring 24 is provided which when the arresting member314 is moved back by means of a hand lever 25 bringsabout the opening of boot fastener 11.

The operation of the safety ski binding according to the invention can be gathered particularly clearly from FIGS. 5a to 5e. 1 7

As can be seen, by reducing the width of the arresting I surface 13 the contact surfaces 15 gradually converge I downwardly so that the spacing of the engagement points of arresting member 14 on arresting surface 13 gradually becomes narrower from a, via b, c and d to 2. This leads to a constant reduction of thelateral release force which is brought about by changing the arresting force lever arm as is desired in many cases. A further effect for reducing the lateral release force is obtained by gradually decreasing downwards the radialspacing of arresting surface 13 from shaft 17.

The slide 14 forming the arresting member can also be replaced by a pivoting shaft or the likewhich pivots about an articulation fitted to the underside of the housing.

The operation of the safety ski binding according to the invention is explained hereinafter relative to FIGS.

If e.g. as a result of a frontal fall a force ofpredetermined size is upwardly exertedon bootfastenerll according to FIG. 1, the latter moves upwards and the contact points or, areas of arresting member 14 on atresting surface 13 slide downwards along contact surfaces 15 on arresting surface 13. This process is shown in different phases in FIGS. 5a to 5e. The continual 1 downward convergence of contact surfaces 15due to a continual narrowing of the radial sections from the top to the bottom is not only shown in FIGS. 5a to Sc but also by means of the broken lines 15 in the vertical longitudinal sections.

Approximately until reaching the position according to section 0 B lugs 20 or 20' and projections 19 or ara resting member 14 remain in engagement so that a lat-' eral release is impossible On further raising the boot fastener 11 the projections 19 or the arrestingmember 14 are disengaged from lugs 20 or 20', and only when there is a lateral force of particular size that the front portion of boot fastener 11 can move laterally relative to the vertical rotating shaft 11a, whereby arresting member 14 is pressed back further counter to the force of spring 26. During this lateral movement only that one of the two projections 14a, 14b located on the side to which the swinging out takes place remains in contact with arresting surface 13. Therefore on swinging to the left as shown in FIG, 4, only projection 14a remains in engagement with arresting surface 13, whilst projection 14b is raised from the arresting surface 13.

Therefore, whereas with a horizontal central position of boot fastener 11 there are always two contact surfaces between arresting member 14 and arresting surface 13, with a lateral deflection of boot fastener 11 there is only one contact point. As a result of the construction of the arresting surface 13 according to the invention, this does not alter the vertical release characteristics of the binding.

Due to the fact that with boot holder 11 open according to FIG. 3 the furthest front point of arresting member 14 is close to vertical shaft 17 it is possible to return the boot fastener 11 from the laterally deflected position of FIG. 4 into the horizontal central position by only exerting a limited force. a

The binding is closed simply by the skier pressing on pedal 22 with the heel, whereupon arresting member 14 passes beyond the peak 21 on arresting surface 13 so that the binding snaps shut. The articulated arrangement of pedal 22 by means of shaft 33 makes it possible for boot fastener 11 to move downwards until it engages with the heel or sole in the area of the toes, and presses downwards against the ski or base plate.

When opening by hand the hand lever 25 is moved upwards according to FIG. 1, whereupon e.g. by means of a pin 38 which works in a recess 39 the arresting member 14 is moved backwards counter to the force of spring 26. As a result of the action of leg spring 24 boot fastener 11 is pivoted upwards. As soon as arresting member 14 has passed beyond peak 21 the boot fastener 11 remains in the uppermost position shown in FIG. 3 even if hand lever 25 is released again.

It is pointed out that in addition to a vertical and lateral release, it is also possible for release to take place in any random diagonal direction, whereby the two above-described basic release characteristics cooperate in component-like manner.

In the practical construction of a binding according to the invention, it should be noted that the lateral release characteristic is determined by the following parameters which are freely selectable within the scope of the invention:

a. Position of the vertical shaft 17 between the transverse shaft 18 and arresting surface 13.

b. The spacing of contact surfaces on arresting surface 13.

c. The horizontal tangents of arresting surface 13 or arresting edge 16 in the area of the contact surfaces between arresting member 14 and arresting surface 13.

FIGS. 6 and 7 show an embodiment wherein additionally a boot fastener 11 divided in the centre of the binding in the longitudinal direction of the ski and a correspondingly divided arresting surface are provided. With a horizontal release according to FIG. 7 the complete boot fastener 11 no longer pivots but instead only half thereof pivots either to the left (FIG. 7) or to the right. Therefore the ski boot is released even more easily. In this case pedal 22 is linked with vertical rotating shaft 11a so that it no longer swings out. Advantageously each half is pivotable about its own vertical shaft.

' The central position of the two boot fastener halves is ensured by a not shown stop member.

While there has been described and illustrated the preferred embodiments of the invention, it is to be understood that these are capable of variation and modification, and it is therefore not desired to be limited to the precise details set forth, but to include such modifications and alterations as fall within the scope of the appended claims.

What is claimed is:

l. A safety skibindinghaving a hollow boot fastener adapted to be swung upwardly out of a normal boot fastening position about a transverse shaft and laterally about a vertical shaft counter to arresting forces, an arresting surface provided on the inside on said boot fastener, an arresting member cooperable with said arresting surface, spring means biasing said member in the direction of the boot into engagement with said arresting surface, said arresting surface having a plurality of vertical arresting cams which rise to a vertical release point during a vertical movement relative to the arresting member and superimposed also a plurality of lateral arresting cams which rise to lateral release points during a lateral movement relative to the arresting member, the lateral arresting cams having centers of curvature located on the side of the arresting surface towards the boot, and said arresting member having two arresting projections movable into engagement with the arresting surface on both sides of a central longitudinal plane thereof when the boot fastener is in a central position.

2. A safety ski binding according to-claim 1, wherein the arresting member is curved between said two arresting projections, said member being curved in the same direction and greater than said lateral arresting cams.

3. A safety ski binding according to claim 2, wherein the width of said arresting surface increases downwards in a manner such that the spacing of the contact surfaces between the arresting member and the arresting surface decreases downwards.

4. A safety ski binding according to claim 1, including a housing, said boot fastener having a vertical rotating shaft which is attached to said housing in a manner so as to pivot about the transverse shaft and carries the front portion of the boot fastener pivotable about the vertical shaft, said vertical shaft being located between the transverse shaft and the arresting surface.

5. A safety ski binding according to claim 4, wherein said arresting surface extends downwardly to the vicinity of the vertical shaft.

6. A safety ski binding according to claim 2, wherein the curvatures of said lateral arresting cams and said arresting member are circular.

7. A safety ski binding according to claim 1, wherein the arresting surface comprises two surfaces substantially homologous to the central longitudinal plane.

8. A safety ski binding according to claim 1, wherein the curvature of radial sections of the arresting surfaces increases from top to bottom.

9. A safety ski binding according to claim 1, including a housing having projections provided thereon, said boot fastener having lugs thereon cooperable with said housing projections with the binding closed in a manner such that lateral release is blocked within a predetermined upward pivoting range of the boot fastener.

10. A safety ski binding according to claim 1, wherein the vertical cams have a first portion along 7 which a substantially constant holding down force is exerted on the boot fastener, said first portion being followed by a second portion having a rising holding down force, and said second portion being followed by a peak where the holding down force disappears.

11. A safety ski binding according to claim 10, wherein following the peak the cams fall away whereby a force is exerted on the boot fastener in the opening direction.

12. A safety ski binding according to claim 1, including a lever for moving the arresting member away from the arresting surface counter to thebias of said spring 8 means, a housing, and a spring between the housing and the boot fastener biased in the opening direction. 13. A safety ski binding according to claim 1,

wherein the front edge of the arresting member is 0 at the center of the binding in the longitudinal direction of the ski, whereby only the right-hand portion of;the boot fastener pivots to the right and the left-hand portion pivots to the left. 

1. A safety ski binding having a hollow boot fastener adapted to be swung upwardly out of a normal boot fastening position about a transverse shaft and laterally about a vertical shaft counter to arresting forces, an arresting surface provided on the inside on said boot fastener, an arresting member cooperable with said arresting surface, spring means biasing said member in the direction of the boot into engagement with said arresting surface, said arresting surface having a plurality of vertical arresting cams which rise to a vertical release point during a vertical movement relative to the arresting member and superimposed also a plurality of lateral arresting cams which rise to lateral release points during a lateral movement relative to the arresting member, the lateral arresting cams having centers of curvature located on the side of the arresting surface towards the boot, and said arresting member having two arresting projections movable into engagement with the arresting surface on both sides of a central longitudinal plane thereof when the boot fastener is in a central position.
 2. A safety ski binding according to claim 1, wherein the arresting member is curved between said two arresting projections, said member being curved in the same direction and greater than said lateral arresting cams.
 3. A safety ski binding according to claim 2, wherein the width of said arresting surface increases downwards in a manner such that the spacing of the contact surfaces between the arresting member and the arresting surface decreases downwards.
 4. A safety ski binding according to claim 1, including a housing, said boot fastener having a vertical rotating shaft which is attached to said housing in a manner so as to pivot about the transverse shaft and carries the front portion of the boot fastener pivotable about the vertical shaft, said vertical shaft being located between the transverse shaft and the arresting surface.
 5. A safety ski binding according to claim 4, wherein said arresting surface extends downwardly to the vicinity of the vertical shaft.
 6. A safety ski binding according to claim 2, wherein the curvatures of said lateral arresting cams and said arresting member are circular.
 7. A safety ski binding according to claim 1, wherein the arresting surface comprises two surfaces substantially homologous to the central longitudinal plane.
 8. A safety ski binding according to claim 1, wherein the curvature of radial sections of the arresting surfaces increases from top to bottom.
 9. A safety ski binding according to claim 1, including a housing having projections provided thereon, said boot fastener having lugs thereon cooperable with said housing projections with the binding closed in a manner such that lateral release is blocked within a predetermined upward pivoting range of the boot fastener.
 10. A safety ski binding according to claim 1, wherein the vertical cams have a first portion along which a substantially constant holding down force is exerted on the boot fastener, said first portion being followed by a second portion having a rising holding down force, and said second portion being followed by a peak where the holding down force disappears.
 11. A safety ski binding according to claim 10, wherein following the peak the cams fall away whereby a force is exerted on the boot fastener in the opening direction.
 12. A safety ski binding according to claim 1, including a lever for moving the arresting member away from the arresting surface counter to the bias of said spring means, a housing, and a spring between the housing and the boot fastener biased in the opening direction.
 13. A safety ski binding according to claim 1, wherein the front edge of the arresting member is formed by the generatrix of a roller which is rotatable about the transverse shaft and is fitted to the arresting member.
 14. A safety ski binding according to claim 1, wherein the front portion of the boot fastener is divided at the center of the binding in the longitudinal direction of the ski, whereby only the right-hand portion of the boot fastener pivots to the right and the left-hand portion pivots to the left. 